Method of and means for making radiographs



June 13, 1939.

T. s. BUCKLEY 2,161,796

METHOD OF AND MEANS FOR MAKING RADIOGRAPHS Filed March 26, 1957 3 Sheets-Sheet l q x7"; 1;}? x4. 42

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INVENTOR 7211101115 5. Buckley BY 7 em ATTORNEY June 13, 1939. T. s. BUCKLEY METHOD OF AND MEANS FOR MAKING RADIOGRAPHS 3 Sheets-Sheet 5 INVENTOR Filed March 26, 1937 Firm/11y J. Bur/{11y W ATTORNEY Patented June 13, 1939 UNITED STATES PATENT OFFICE Timothy S. Buckley, Jackson Heights, Long Island, N. Y.

Application March 26, 1937, Serial No. 133,134

3 Claims.

This invention relates to a method and means for making radiographs, more especially in the form of X-ray negatives taken through an interposed medium which varies in its degree of penetrability, to X-rays over different portions of said negative. For convenience in description, the interposed medium is to be understood as including in a general way all objects photographically recorded on the negative as well as the space extraneous thereto through which the X-rays pass from an X-ray source to the sensitized layer of a plate, film, or the like.

The object of this invention is to provide a simple and efiective method and means for vary- 16 ing the efiects of X-rays on different portions of a sensitized layers exposed to the X-rays through an interposed medium which varies in its permeability to said rays for difierent portions of said layer. The method consists in a general way in controlling the relative permeability of the interposed medium overlying different areas of the sensitized layer; or in separately regulating the duration in the exposure of one portion of the negative with respect to other portions or in combining these functions.

One object of the invention is to provide a timing device for predetermining the variable duration of a period of exposure for one portion of a sensitized layer relatively to other portions,

said timing device being separately controlled and independently timed with respect to the timing switch which is adjustable for predetermining the energizing periods of the X-ray source in the usual manner.

Another object of the invention is to provide a practical form of marking plaque for general use on negatives exposed to X-rays under a wide voltage range, said plaque being capable of undergoing extended periods of storage and resistant to heat, dryness, and moisture without seriously interfering with its capacity to receive and retain an impressed inscription under a scribing pressure. Other objects of the invention relate to certain features described in the specification and recited in the claims. While the drawings show practical and convenient means for reducing the invention to practice, it will be understood that various alterations and modifications within the scope of the appended claims may be resorted to when desired.

In the drawings,

Fig. 1 is a perspective view of an X-ray machine suitable ior use in hospitals and other institutions with one perferred embodiment of my BB invention illustrated in the form of an accessory;

Fig. 2 is a face view of a preferred form of the novel marking or autographic plaque, portions of the component layers being broken away and removed to show the construction;

Fig. 3 is a partial longitudinal section of the 5 plaque taken on the line 3-3 of Fig. 2;

Fig. 4 is a side elevation of the exposure timing device for the marking or autographic plaque, certain portions hereinafter referred to being shown in section;

Fig. 5 is a front elevation of the timing mechanism for regulating the exposure of the plaque and corresponds to a section on the line 5-5 of Fig. 6;

Fig. 6 is a section on the line 6--6 of Fig. 5 and shows a side elevation of the timing mechanism within the closed housing;

Fig. 7 is a horizontal section of the timing mechanism corresponding to the line |l of Fig. 5, the plaque-supporting frame being shown in extended position;

Fig. 8 is an exploded view in perspective of the screen and shutter control mechanism, parts being omitted;

Fig. 9 is a wiring diagram for the embodiment of my invention shown in Fig. 1; and

Fig. 10 is a side elevation of another embodiment of my invention and wiring diagram therefor.

According to Figs. 1 to 9 of the drawings, a movable base 15 carries a current control and metering unit I! suitable for X-ray machines such as those employed in hospitals and other institutions. Leading to and from the primary coil of a transformer within the control and metering unit [1, is a double wire electric cable I8, a second double wire cable l9 including high tension wires extending from the secondary coil of the transformer to an X-ray projector 20 which is trunnioned by pivot pins 2| in a yoke or bracket 22 mounted at the outer ends of supporting rods 23, said rods being carried by a collar 24 which is adjustable vertically on a post 25. A casette comprising plate 26 in a frame 21 on a table 28, is arranged below the projector 20. Detachably suspended at one side of the control unit I1, is a timing switch 29 which, in accordance with usual practice, may be set for predetermining the duration of exposure by closing an energizing circuit through the projector 20 for the required period of time. Extending from control unit I1, is a double wire cable 35 which is connected to a timing device 36 whereby the exposure of a limited area of the sensitized layer is regulated independently of the 56 timed energization of the X-ray source to which said layer is exposed. As shown in Figs. 4, 6 and '7, this device, in its preferred form, comprises a frame 31 provided with side bars 38 pivoted at 39 to the housing of said timing device, a marking plaque P of the character to be hereinafter described being suitably disposed therein for photographically marking the negative. Suitable means for interrupting the exposure of the limited area of the sensitized layer under the marking plaque are illustrated in the form of a frame 69 provided with laterally-spaced arms 4| pivoted at 42 to the inner end walls of timing device 36. Mounted within the frame 48 is a sheet lead screen S which is substantially impenetrable to X-rays. Projecting rearwardly from the screen-supporting frame 40 in its raised position, is a zig-zag detent plate 43 arranged to be releasably engaged by a claw on the outer end of a radial arm 44 which projects from a collar =15 on an oscillatory member 46 and is yieldably retained in engagement with detent plate #3 by means of a helical spring 44 The member :16 pivots at opposite ends in plates 41 and carries a radial arm 48 which is normally retained in engagement with a stop pin 48 by the spring 44 A radial plate or tappet 49 formed by the deflected outer end of a strap 58 on an oscillatory spindle 5| is arranged to strike the radial arm 48 for releasing the detent plate 43 from. engagement with claw 44 near one extreme of movement of spindle 51. As shown in Fig. 5, the spindle is rotatably mounted at its lower end in lower plate 41 and at its upper end is freely pivoted in a conical recess 52 formed in a disk 53. The disk 53 has its top surface in frictional engagement with upper plate 41, a split resilient washer 54 being interposed between said plate 1 and a circular abutment 55 secured to the stem 56 which extends upwardly from the disk 53 and carries a finger grip 51. A radial pointer 58 on stem 56 is movable over a graduated disk 59 whenever disk 53 is turned by the finger grip 51 for regulating the marking period of exposure for that portion of the negative which is to carry the identifying marking. Mounted in the periphery of disk 53 and projecting downwardly is a stop pin 68 for limiting the clockwise displacement and determining the variable initial position of a radial arm. 6| which projects from the spindle 5 l said arm 6| being normally pressed against the stop 68 by a resilient connection in the form of a tensioned coil spring 62 which is connected at its outer end to a fixed pin 63 on the under side of disk 53 and at its inner end to the reduced upper end of spindle 5|. Under these conditions, the tappet arm 49 will engage the radial arm 48 on member 46 and release the screen-supporting frame 48 after a counterclockwise displacement of radial arm 6| in an amount depending upon the angular setting of adjustable stop 68 with respect to a fixed stop pin 54 which depends from upper plate 41 to limit the counterclockwise displacement of a radial pin 65 on disk 53. Keyed to the lower end or spindle 5| is a spur gear 66 which meshes with a spur pinion 61 on the rotor shaft 68 of a small induction motor 69, said motor being connected by cable 35 to the primary circuit of a transformer as shown in Fig. 9.

Referring now to Fig. 9, service lines 10 and 1| lead to and from the primary coil 12 of a transformer, the secondary coil 13 of said transformer being connected to the X-ray tube (not shown). The line 1! of the primary circuit includes a normally open switch 14 which is operated by a plunger 15 in' a solenoid 16; said solenoid being connected in series with the induction motor 69 and timing switch 29 through wires 11, 18; 19, 88, BI, 82; 83; 84; 85 and 86; The timing switch 29, which is of the usual type employed on X-ray machines for predetermining the length and termination of the period of time during which an X-ray source is to be energized for the proper amount of exposure for each negative, is shown diagrammatically in Fig. 9. Said timing switch includes a bridge contact 81 normally removed from but movable into engagement with spaced contacts 88 by means of a manually operated plunger 85 against the resistance of a coil spring 86. This operation closes the motor-energizing circuit which remains closed until the energization of the X-ray source is terminated by the automatic opening of the circuit by the timing switch 29. Assuming for the purpose of illustration that an X-ray of the cranium is to be identified by the subjects photographically recorded signature, in view of the high tension currents employed for X-rays of this character and for the purpose of preventing an over exposure of that portion of the negative to be marked by said signature, adjustable stop 60 (Fig. 8) is set at a small angular displacement from the shutter releasing position of radial pin 6|, the tension in spring 62 being such that the pin 6| is pressed into engagement with stop 60 until displaced therefrom by motor 69. Timing switch 29 having been set to provide the prolonged exposure required by an X-ray of the cranium, plunger I (Fig. 9) is depressed, solenoid 16 and motor 69 are energized and the transformer becomes active for supplying the necessary high tension currents to the Coolidge tube. As the motor 69 becomes active, arm 6| is moved from stop 60 and after a brief angular displacement, the tappet plate strikes the radial arm 48 and causes the release of shutter 40 and thus permits the screen S of lead to cover the name plaque P (Fig. 4) after its brief exposure such that a clear and unmistakable photographic record of the signature is produced notwithstanding the continued exposure of the main portion of the negative to the high tension rays. It will be understood that while the energization of motor 69 continues throughout the main exposure of the X-ray negative, the fixed stop 64 blocks the movement of radial pin '65 while the increased tension in spring 62 stalls the motor 69 until the motor circuit is broken at the timing switch 29 when the spring 62 operates to return the pin 6! into engagement with stop62 in readiness for another X-ray. As shown in Fig. 9, the embodiment of my invention illustrated in Fig. 1 may be applied as an accessory to any modern X-ray machine in which the timing switch 29 is usually connected directly to the primary circuit of the transformer by means of a plug 9.3 connected to the wires 83 and 84 and provided with contacts to be plugged into the sockets 18* and 86 at the ends of wires 18 and 86. It will be understood therefore that the removal of the timing switch plug 93 and the introduction of the Y-connection having a plug 89 and sockets 90 and 9| enable the automatic timing of the screen shutter to be rendered effective in a simple manner.

Where it may be desired to permanently incorporate the apparatus in an X-ray machine, this may be done in the manner shownin Fig. 10, in which a'timing switch is connected to the primary mains 96 and 91 in series with a solenoid 98 which closes a switch 99 to energize the primary coil I00 of the transformer of which the secondary coil I0l is connected to the X-ray tube. Connected to the mains 96 and 91 are the wires I02 and I03 of a cable which extends to an electroresponsive device such, for example, as an electromagnet I04 provided with a core.l05 arranged to attract an armature carried by one arm of a detent lever I06 pivoted at I01 on an adjustable base or panel I08. A thumb screw I09 which is threaded into a block I I0 mounted on the panel I08 is movable laterally along an arcuate slot l l i for securing the panel in any desired position. The other arm of detent lever I06 is provided with a claw I I! which normally engages the outer edge of a screen-supporting plate H3 which is maintained under the tension of a spring Il l for propelling a lead screen H5 through variable angular distances to cover the marking plaque which has been placed in the plaque supporting frame H6.

In my copending application Ser. No. 23,175, which was filed in the U. S. Patent Office on May 24, 1935, is shown and described a plaque for autographing an X-ray negative by photographic exposure. According to said application, this plaque comprises a card or backing of permeable material coated with material substantially impermeable to X-rays and covered with a sheet of Cellophane. As thus constructed, the plaque is ready to have an inscription formed in the impressionable intermediate layer or coating by a scribing pressure applied to the Cellophane cover. This device is conveniently employed for identifying the patient or other person of whom an X-ray negative is about to be made since the signature of the subject is readily formed as depressions in the intermediate layer along which the plaque becomes more permeable to the X-rays in such a way that the signature is photographically recorded on the negative when the plaque is arranged as part of the intervening medium between an X-ray source and the sensitized layer. The plaque referred to is therefore suitable for use in the above-described machine. The present invention provides a plaque of unchanging form for various kinds of X-ray negatives which may require X-rays of any power within a wide power range. In order to secure the proper amount of exposure for that portion of the sensitized layer disposed beneath the marking plaque, an adjustable timing device for obtaining predetermined duration of the marking exposure is controlled separately and independently of the timing switch which controls the energization of the X-ray source. Figs. 2 and 3 of the drawings show a plaque for this purpose which is durable and suitable for quantity production and capable of resisting heat, dryness and moisture without losing its capacity for receiving and retaining depressions formed therein by a scribing pressure. It comprises, in the form shown, a back layer or plate 30 of material having a hard smooth surface, said layer being permeable to X-rays and impervious to moisture or moisture-laden air; a plastic coating 3| of material impermeable to X-rays; and a covering layer 32 having soft and non-resilient physical properties which permit the formation of depressions in the plastic coating 3| by a scribing pressure exerted through the covering layer 32. For example, such a plaque may be composed of a small plate of glass coated with a thick paste of white lead in a vehicle such as linseed oil or castor oil and covered by a sheet of aluminum which has soft and non-resilient physical properties. Preferably a complete marginal seal 34 of suitable material for resisting heat, dryness and moisture, is provided.

I claim:

1. In combination with an X-ray machine having an exposure-timing switch, an X-ray screen movable from a normally removed position to a covering position in respect to a portion of a sensitized layer positioned for exposure in said X-ray machine, a screen-controlling member, a timing device comprising relatively movable members for determining a variable duration of exposure prior to the movement of said screen to covering position, one of said timing device members being adjustable to predetermine the initial position of the other timing device member, a yieldable connection between said timing device members, said connection being stressed for returning said other timing device member to initial position and tending to retain it there after each displacement therefrom, electro-responslve means under the control of said timing switch, and an operating connection between said electro-responsive means and said screen-controlling member, said operating connection including members movable with said screen-controlling member and said other timing device member respectively for the actuation of the former by the latter.

2. In an X-ray machine having a sensitized member to be exposed to the action of an X-ray projector, a screen movable into and out of position to cover a portion of the sensitized member; a power source; a timing switch and connections to control the power source to variably predetermine the duration of energization of the projector and to determine the initiation of the movement of the screen into covering position; and operating means to move the screen into covering position, including a device responsive to initial actuation by said timing switch but adjustable independently thereof to variably predetermine the period during which said portion of the member is to remain exposed.

3. In an X-ray machine having a casette to be exposed to the action of an X-ray projector, the combination with supporting means of a pivotally mounted frame to receive an identifying plaque, which frame when moved into one position overlies the casette, and a pivotally mounted screen impermeable to X-rays positioned to be moved to overlie the plaque.

TIMOTHY S. BUCKLE'Y. 

